Research Reports on Mathematical and Computing Sciences Department of Mathematical
نویسندگان
چکیده
Goldwasser and Kharchenko (TCC 2006) showed a proof of plaintext knowledge for the AjtaiDwork cryptosystem and left the open problem designing a proof of plaintext knowledge for the Regev’04 cryptosystem (JACM 2004). In this paper, we show a proof of plaintext knowledge for the Regev’04 cryptosystem (JACM 2004) using their technique. Furthermore, we show that it can be applied to the Regev’05 cryptosystem (STOC 2005). The key idea is to analyze tradeoffs between the hardness of the underlying lattice problem and the variance of ciphertexts, which given by Kawachi, Tanaka, and Xagawa (SCIS 2006).
منابع مشابه
Research Reports on Mathematical and Computing Sciences Department of Mathematical and Computing Sciences Tokyo Institute of Technology
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